1. Field of the Invention
The present invention relates generally to an image reader for photoelectrically reading an original image or the like recorded on an image recording medium such as a film, and more particularly to an image reader and an image reading method capable of preventing an adverse influence of noise components including silver components by detecting the noise components remaining in an image recording medium such as a film.
2. Description of the Related Art
Nowadays, a so-called direct exposure, in which a film image is exposed by projecting light onto a photosensitive material, is a major method for printing onto the photosensitive material (photographic printing paper) the image recorded on a photographic film (which will hereinafter be simply called a film) such as a negative film and a reversal film.
Further, a digital photoprinter has been utilized over the recent years, in which the image recorded on the film is photoelectrically read; the read-out image has been converted into digital signals; image data for recording are thereafter obtained by effecting a variety of image processing operations; a photosensitive material is exposed to recording beams modulated in accordance with the image data to obtain a print; and the print is then outputted.
According to the thus constructed digital photoprinter, the image recorded on the film is read, and the digital image data undergo the image processing. It is therefore possible to highly preferably correct color and density thereof and further obtain a high-quality image by executing the image processing such as gradation correction and sharpness enhancement (sharpness correction), which cannot be basically implemented by direct-exposure type normal printers.
Moreover, the digital photoprinter outputs the print and, in addition, outputs (stores) the image data as an image file onto a recording medium such as a CD-R, HD (hard disk) and so on.
By the way, what is known as one factor of a quality decline of the print image in those photoprinters is silver components remaining in the image (which will hereinafter be called residual silver) on the developed (silver halide photographic) film.
A so-called color film is basically designed to remove all the existing silver components by bleaching and fixing executed after coloring/development.
If the processing is not properly executed due to deterioration of a processing liquid and in terms of temperature control, however, the silver components cannot be completely removed because of an occurrence of defect in the bleaching and fixing operations, with a result that the residual silver stays therein.
If the residual silver exists in the image, a variety of declines of image quality arise, in which a gradation of a high-density portion (highlight on the print) becomes hard, a saturation decreases, and so forth.
Accordingly, a production of the print with the high-quality image reproduced involves eliminating an adverse influence caused by the residual silver. Under the present conditions, however, there is no alternative effective method but to prevent the residual silver from remaining in the image by properly managing the bleaching and fixing operations in developing the film.
In addition to an image-forming intermediate product in an image recording medium, including residual silver remaining in a film, an impurity remaining in an image recording medium may induce declines of image quality. In order to avoid such declines of image quality, there is no alternative effective method but to prevent the impurity from remaining in the image as is the case with residual silver.